Bonded keyboard and method for making the same

ABSTRACT

A bonded keyboard and method for making the same are disclosed. The bonded keyboard uses adhesive as the primary agent, and in some embodiments, as the sole agent for coupling various components of the keyboard stackup together. The keyboard stackup uses a skeletal adhesive to couple a top case to a backcase assembly. In one embodiment, the skeletal adhesive is an interconnected matrix of ribs dimensioned to fit within the spacing existing between adjacent keys, which are mounted on the backcase assembly. The skeletal adhesive is fixed to the backcase assembly, occupies a portion of the spacing that exists between keys, and the top case is fixed to the top of the skeletal adhesive.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/578,687, filed Dec. 21, 2011, the disclosure of which is incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The disclosed embodiments relate generally to electronic devices, and more particularly, to input devices for electronic devices.

BACKGROUND OF THE DISCLOSURE

Many electronic devices typically include one or more input devices such as keyboards, touchpads, mice, or touchscreens to enable a user to interact with the device. These devices can be integrated into an electronic device or can stand alone as discrete devices that can transmit signals to another device either via wired or wireless connection. For example, a keyboard can be integrated into the housing of a laptop computer or it can exist in its own housing.

It is often desirable to reduce the size of electronic devices and minimize machining costs and manufacturing time of such devices. For example, laptops may be designed to be as small and light as possible, but input devices such as a keyboard may occupy relatively large portions of the available interior space. Accordingly, what is needed is an improved keyboard design.

SUMMARY OF THE DISCLOSURE

A bonded keyboard and method for making the same are disclosed. The bonded keyboard uses adhesive as the primary agent, and in some embodiments, as the sole agent for coupling various components of the keyboard stackup together. The keyboard stackup uses a skeletal adhesive to couple a top case to a backcase assembly. In one embodiment, the skeletal adhesive is an interconnected matrix of ribs dimensioned to fit within the spacing existing between adjacent keys, which are mounted on the backcase assembly. The skeletal adhesive is fixed to the backcase assembly, occupies a portion of the spacing that exists between keys, and the top case is fixed to the top of the skeletal adhesive.

In one embodiment, a bonded keyboard can include a backcase assembly and several of keys mounted on the backcase assembly and arranged in a predetermined configuration such that spacing exists between adjacent keys. The keys can include outer keys that a define a periphery. The backcase assembly can include a feature plate, an adhesive layer and a membrane, the membrane bonded to the feature plate with the adhesive layer. The keyboard also includes a skeletal double sided adhesive layer secured to the backcase assembly and constructed to occupy a portion of the spacing and a portion of the periphery and a top case secured to the skeletal double sided adhesive.

In another embodiment, a computing device has a bonded keyboard including a backcase assembly having top and bottom surfaces, several keys mounted to the top surface of the backcase assembly, the keys arranged such that spacing exists between adjacent keys, a skeletal double sided adhesive layer mounted to the top surface of the backcase assembly, the adhesive constructed to surround each key by occupying a portion of the spacing existing between adjacent keys, and a top case including a skeletal structure secured to the adhesive layer.

In another embodiment, a method for assembling a keyboard includes mounting a plurality of keys to a backcase assembly, applying a skeletal double sided adhesive layer to the backcase assembly, the skeletal adhesive layer surrounding at least one of the keys, and securing a top plate to the backcase assembly via the skeletal adhesive, the top plate constructed to mimic construction of the skeletal adhesive layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and advantages of the invention will become more apparent upon consideration of the following detailed description, taken in conjunction with accompanying drawings, in which like reference characters refer to like parts throughout, and in which:

FIG. 1 shows an illustrative exploded view of bonded keyboard 100 in accordance with an embodiment;

FIG. 2 shows a simplified top view of a feature plate n accordance with an embodiment;

FIG. 3 shows a simplified illustrative top view of adhesive layer 120 in accordance with an embodiment;

FIG. 4 shows a simplified illustrative top view of membrane in accordance with an embodiment;

FIG. 5 shows a simplified top view of skeletal double sided adhesive layer in accordance with an embodiment;

FIG. 6 shows an illustrative top view of top case in accordance with an embodiment;

FIG. 7 shows an illustrative perspective view of a section of keyboard including a key in accordance with an embodiment;

FIG. 8 is an illustrative cross-sectional view of the keyboard of FIG. 7 in accordance with an embodiment;

FIG. 9 is an alternative illustrative cross-sectional view of FIG. 7 in accordance with an embodiment;

FIG. 10 shows an illustrative top view of a section of a keyboard in accordance with an embodiment;

FIG. 11 shows a perspective view of a computing device having a keyboard incorporated therein in accordance with an embodiment; and

FIG. 12 shows an illustrative flowchart for making a bonded keyboard according to an embodiment.

DETAILED DESCRIPTION OF THE DISCLOSURE

FIG. 1 shows an illustrative exploded view of bonded keyboard 100 in accordance with an embodiment. Keyboard 100 is a stackup (shown as stackup 102) of several components that are connected together. Stackup 102 can include feature plate 110, adhesive layer 120, membrane 130, keys 140, skeletal double sided adhesive layer 150, and top case 160. Illustrative top views of each component are shown in FIGS. 2-6. When keyboard 100 is assembled, feature plate 110 may form the bottom of the stackup, top case 160 forms the top of the stackup, and the other components are sandwiched therebetween. In other embodiments, a backlight (not shown) may form the bottom of the stackup, as it can be mounted under feature plate 110. In yet another embodiment, a backlight can be positioned between feature plate 110 and membrane 130. In a further embodiment, a backlight can be integrated with feature plate 110.

The components of keyboard 100 can be held together primarily or exclusively with bonding, with minimal or no use of fasteners. Bonding is achieved by adhesive layers 120 and 150. Fasteners (not shown in FIGS. 1-6) assist in holding keyboard 100 together by coupling feature plate 110 to topcase 160. FIGS. 2-6 show fastener through-holes 170 through which fasteners are inserted. A more detailed discussion of fasteners is discussed below with reference to FIG. 10.

Adhesive layer 120 bonds feature plate 110 to the bottom surface of membrane 130 and adhesive layer 150 bonds topcase 160 to the top surface of membrane 130. Each one of keys 140 has a mechanism (not shown) that secures it to membrane 130 and/or feature plate 110. Using adhesive layers 120 and 150 as the primary bonding agent simplifies construction of the stackup, reduces cost, reduces thickness of the keyboard, minimizes or completely eliminates use of fasteners, and enhances water proofing. An additional benefit realized with the bonded keyboard is a reduction of vibrations compared to contemporary keyboards built with a substantial number of fasteners.

Turning now to FIGS. 2-6, each component of stackup 102 is discussed in more detail. FIG. 2 shows a simplified top view of feature plate 110. Feature plate 110 may form a bottom of stack 102 and may be operably connected to keys 140. For example, feature plate 110 can include contacts (not shown) for conducting electrical signals. As another example, feature plate 110 can include anchoring points (not shown) for securing keys 140. Feature plate 110 can optionally include fastener through-holes 170, as shown. Through-holes 170 may be positioned on the periphery and in a few locations of the interior portion of feature plate 110. The number of through-holes 170 located in the interior portion is substantially limited. This is in direct contrast to contemporary keyboards, which have such through-holes distributed in substantial numbers throughout the interior portion.

FIG. 3 shows a simplified illustrative top view of adhesive layer 120. Adhesive layer 120 can be any suitable double sided adhesive. For example, adhesive 120 can be a pressure sensitive adhesive or a heat activated adhesive. In one embodiment, adhesive 120 can have a PET substrate with adhesive affixed on both sides. Adhesive 120 can have a thickness ranging between 0.02 mm to 0.1 mm, or more particularly, between 0.03 mm to 0.05 mm. Adhesive layer 120 can optionally include fastener through-holes 170. The position of through-holes can align with through-holes 170 of feature plate 110.

FIG. 4 shows a simplified illustrative top view of membrane 130. Membrane 130 can be sensing membrane that includes one or more sensors (not shown) for detecting whether any of keys 140 have been selected by a user. The sensors can be made from indium tin oxide (ITO), for example. Membrane 130 can optionally include fastener through-holes 170. The position of through-holes can align with through-holes 170 of feature plate 110 and adhesive layer 120.

The collective combination of feature plate 110, adhesive layer 120, and membrane 130 may be referred to herein as a backcase assembly. The backcase assembly can be a sub-assembly made prior to final assembly of keyboard 100.

Referring to FIG. 1, keys 140 can be any suitable keys for use in a keyboard. Keys may, for example, use a scissor-based support mechanism that couples a key cap to membrane 130 and/or feature plate 110. The keys can be arranged in a predetermined configuration of outer keys 141 that form a periphery and inner keys 142 that exist within the periphery. Spacing exists between all the keys.

FIG. 5 shows a simplified top view of skeletal double sided adhesive layer 150. Adhesive layer 150 can be any suitable double sided adhesive such as, for example, a pressure sensitive adhesive or a heat activated adhesive. In other embodiments, adhesive layer 150 can be screen printed or pad printed, and can use wet or UV curing. In one embodiment, adhesive 150 can have a PET substrate with adhesive affixed on both sides. Adhesive 150 can have a thickness ranging between 0.005 mm to 0.1 mm, or more particularly, between 0.03 mm to 0.05 mm.

Adhesive layer 150 can optionally include fastener through-holes 170. The position of through-holes can align with through-holes 170 of feature plate 110, adhesive layer 120, and membrane 130.

In one embodiment, as shown, the skeletal configuration of adhesive layer 150—an interconnected series of skeletal ribs 154—is designed to surround each one of keys 140. That is, adhesive layer 150 is dimensioned to fit into the spacing that exists between each key. The thickness of the skeletal ribs can be uniform or can vary. For example, the thickness of adhesive layer 150 between adjacent keys 140 (such as between regions 151 and 152) can be a first predetermined thickness and the thickness of the periphery of adhesive layer 150 (such as the region outside of regions 151) can be a second predetermined thickness, where the first predetermined thickness is greater than the second predetermined thickness.

In another embodiment, not shown, the skeletal configuration of adhesive layer 150 can be designed to selectively surround keys. For example, as opposed to surrounding each key individually, layer 150 can surround a group of two or more keys. As a specific example, if two keys are surrounded, no skeletal rib would exist between the adjacent keys.

FIG. 6 shows an illustrative top view of top case 160. Top case 160 can be part of an electronic device such as a laptop or it can be part of a stand alone electronic device such as a wired keyboard. Top case 160 includes skeletal ribs 164 dimensioned to fit within the spacing between keys 140. The same spacing uniformity or variance of the skeletal ribs discussed above in connection with adhesive layer 150 applies to top case 160. Top case 160 can also include an outer periphery region dimensioned to surround keys 140. Top case 160 can optionally include fastener through-holes 170. The position of through-holes can align with through-holes 170 of feature plate 110, adhesive layer 120, membrane 130, and adhesive layer 150.

Both adhesive 150 and top case 160 have structures that mimic each other. This promotes a relatively strong bond between the backcase and top case 160 because the shape of skeletal adhesive 150 maximizes bonding adhesion between the two. Thus, this can eliminate or substantially reduce the use of fasteners to couple the keyboard stackup together.

Reference is now made to FIGS. 7-10 to show spatial relationships of various components as they are stacked up to form keyboard 100. FIG. 7 shows an illustrative perspective view of a section of keyboard 100 including a key 140. FIG. 7 also shows the stackup of feature plate 110, adhesive layer 120, membrane 130, and adhesive layer 150.

FIG. 8 is an illustrative cross-sectional view of keyboard 100 taken along line 8-8 of FIG. 7. This cross-sectional view shows that gaps 810 exist between the edges of key 140 and top case 160. Gaps 810 ensures that key 140 travels freely without interference from top case 160. Gaps 810 may be equidistant or different on both sides of key 140. In addition, gaps 820 exist between skeletal adhesive layer 150 and the edge of key 140. Gap 820 ensures key 140 travels freely and does not get stuck to the adhesive.

Skeletal rib 861 of top case 860 has width, Wtp, as shown, and skeletal rib 851 of adhesive layer 850 has width, Wa, as shown. The width of skeletal rib 861 can be at least the same width of skeletal rib 851 or greater. Such sizing ensures that adhesive layer 150 cannot be seen, even after top case 160 has been applied thereto. The sizing also accounts for differences in manufacturing and assembly tolerances. As shown in FIG. 8, skeletal rib 861 overhangs both sides of skeletal rib 851. It is understood that rib 861 need not overhang rib 851 in this fashion. In another embodiment, rib 861 may overhang one side of rib 851, but both ribs 851 and 861 are substantially aligned at the other side.

FIG. 9 is an alternative illustrative cross-sectional view taken along line 8-8 of FIG. 7. In FIG. 9, fastener 910 is shown coupling feature plate 110 to top plate 160 by passing through feature plate 110, adhesive layer 120, membrane 130, adhesive 150, and top plate 160. In particular, fastener can pass through fastener through-holes 170 of each component. Fastener 910 can be any suitable mechanism for coupling objects together. For example, fastener 910 can be a screw or pin.

FIG. 10 shows an illustrative top view of a section of a keyboard in accordance with an embodiment. Several buttons 140 are shown positioned in apertures of top case 160. Skeletal adhesive 150, shown with dotted lines, surrounds the apertures of top case 160. As discussed above, adhesive 150 is dimensioned such that top case 160 completely covers adhesive 150.

FIG. 11 shows a perspective view of a computing device 1100 having a keyboard 1102 incorporated therein. Computing device 1100 can be any suitable computing device, such as, for example, a laptop computer, a desktop computer, a telephone, smart phone, or gaming device. Keyboard 1102 can be integrally formed within computing device 1100. In other embodiments, a keyboard according to an embodiment can be separate from the computing device and can stand alone as a self-contained device. For example, a keyboard may be a communication interface such as, for example, a wired keyboard or a wireless keyboard that can transmit data to and from a computing device.

FIG. 12 shows an illustrative flowchart for making a bonded keyboard according to an embodiment. Starting at step 1210, a plurality of keys are mounted to a backcase assembly. For example, the keys can keys 140 discussed above in connection with FIGS. 1-10, and the backcase assembly can include a feature plate, adhesive, and a sensor membrane. At step 1220, a skeletal double-sided adhesive layer can be applied to the backcase assembly. The skeletal adhesive layer can surround at least one of the keys. For example, the skeletal adhesive can be skeletal adhesive 150 shown in FIGS. 1, 5, 8, and 10. At step 1230, a top plate is secured to the backcase assembly via the skeletal adhesive. The top plate is constructed to mimic construction of the skeletal adhesive layer such that when it is applied to the top of skeletal adhesive, a strong adhesive bond is formed and the adhesive layer if fully covered by the top case.

It is understood that the order in which the bonded keyboard can vary from that order described above in connection FIG. 12. The bonded keyboard can be constructed using any approach. For example, the skeletal adhesive can be applied to the top plate first, and the combination can then be applied to the backcase assembly.

The described embodiments of the invention are presented for the purpose of illustration and not of limitation. 

What is claimed is:
 1. A bonded keyboard, comprising: a backcase assembly including a feature plate, an adhesive layer and a membrane, the membrane bonded to the feature plate with the adhesive layer; a plurality of keys mounted on the backcase assembly and arranged in a predetermined configuration such that spacing exists between adjacent keys, the keys including outer keys that a define a periphery; a skeletal double sided adhesive layer secured to the backcase assembly and constructed to occupy a portion of the spacing and a portion of the periphery; and a top case secured to the skeletal double sided adhesive.
 2. The keyboard of claim 1, wherein the skeletal adhesive layer comprises a plurality of interconnected skeletal ribs.
 3. The keyboard of claim 2, wherein a first portion of the skeletal ribs has a first predetermined thickness and a second portion of the skeletal ribs has a second predetermined thickness.
 4. The keyboard of claim 1, wherein the skeletal adhesive layer surrounds each one of the keys.
 5. The keyboard of claim 1, wherein the skeletal adhesive layer surrounds select groups of the keys.
 6. The keyboard of claim 1, wherein the skeletal double sided adhesive comprises a one-piece carrier.
 7. The keyboard of claim 1, wherein skeletal double sided adhesive has a thickness ranging between about 0.005 to 0.1 mm.
 8. The keyboard of claim 1, wherein the skeletal double sided adhesive does not interface with any of the keys.
 9. The keyboard of claim 10, wherein the top case mimics the shape of the skeletal double sided adhesive.
 10. The keyboard of claim 1, further comprising at least one fastener that couples the backcase assembly to the top case.
 11. The keyboard of claim 2, wherein the top case comprises top case skeletal ribs, wherein a thickness of the top case skeletal ribs is at least as thick as a thickness of the skeletal ribs of the skeletal adhesive.
 12. A computing device, comprising: a bonded keyboard comprising: a backcase assembly having top and bottom surfaces; a plurality of keys mounted to the top surface of the backcase assembly, the keys arranged such that spacing exists between adjacent keys; a skeletal double sided adhesive layer mounted to the top surface of the backcase assembly, the adhesive constructed to surround each key by occupying a portion of the spacing existing between adjacent keys; and a top case including a skeletal structure secured to the adhesive layer.
 13. The keyboard of claim 12, wherein the keys include outer keys, and wherein the adhesive layer occupies a portion of a periphery surrounding the outer keys.
 14. The keyboard of claim 12, wherein each key has first and second edges, wherein a minimum gap distance exist between edges and an edge of the skeletal adhesive.
 15. The keyboard of claim 12, wherein the backcase assembly is operative to detect key strokes.
 16. The keyboard of claim 12, further comprising fasteners to couple the backcase assembly to the top case.
 17. A method for assembling a keyboard, the method comprising: mounting a plurality of keys to a backcase assembly; applying a skeletal double sided adhesive layer to the backcase assembly, the skeletal adhesive layer surrounding at least one of the keys; and securing a top plate to the backcase assembly via the skeletal adhesive, the top plate constructed to mimic construction of the skeletal adhesive layer.
 18. The method of claim 17, wherein the backcase assembly comprises a feature plate, adhesive layer, and a membrane, the method further comprising: securing the membrane to the feature plate with the adhesive layer.
 19. The method of claim 17, further comprising: using at least one fastener to secure the top case to the back case assembly.
 20. The method of claim 17, wherein the keys are arranged in a predetermined configuration having a periphery defined by outer keys and spacing exists between the outer keys and adjacent inner keys and between adjacent inner keys, and the skeletal double adhesive occupies a portion of the spacing and a portion of the periphery. 